Heater for vehicles

ABSTRACT

A compact heater for vehicles which is fired by fluid fuels and wherein one half of a split casing is arranged in the burner assembly, while the other half carries the combustion chamber and the heat exchanger. The burner assembly includes, in coaxial succession, an electric drive motor, an impeller for the combustion air, a central air guide, a fuel pump and an atomizing nozzle extending therefrom into the burner head at the mouth of the combustion chamber. The casing halves can be pivoted open for convenient access to the parts of the burner assembly.

D Umted States Patent [1 1 1111 3,779,229 Volbehr 1 Dec. 18, 1973 1 HEATER FOR VEHICLES 3.543.742 12 1970 Stump et al 126/116 A 2,757,662 3/1956 Baier et al t 126/110 8 [75] [mammvolbeh" Lochhami' 2,726,042 12/1955 Baier et al 237/123 (3 Germany Assigneei Webasto-Werke Baler Primary Examiner-William E. Wayner StOCkdOrf/Mumch, e y Assistant Examiner-William E. Tapolcai, Jr. [22] Filed: Sept 17, 1971 Atmrney-Arthur Schwartz et al.

[21] Appl. No.: 181,316

[57] ABSTRACT 30 Foreign Application Priority Data A compact heater for vehicles which is fired by fluid fuels and wherein one half of a split casing is arranged O t. 3, 1970 G P 20 48 760.9

0 Emmy in the burner assembly, wh1le the other half carries the [52] CL u 126/110 B 126/116 R 431/186 combustion chamber and the heat exchanger. The 51 1m. (:1. E2411 3/06 assembly includes in Coaxial Succession 581 Field of Search 126/110 R 110 B electric drive motor impeller 126/116 R 116 237/123 431/187 air, a central air guide, a fuel pump and an atomizing 188 353 l89.239/4l6 5 4:173 nozzle extending therefrom into the burner head at the mouth of the combustion chamber. The casing [56] References Cited halves can be pivoted open for convenient access to UNITED STATES PATENT-S the parts of the burner assembly.

1,412,023 4/1922 Erickson 431/186 11 Claims, 1 Drawing Figure Inventor:

HARTW/G VOLBEHR by 1 01 L/ Agen HEATER FOR VEHICLES BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to heaters for vehicles, and more especially to a heater, operated with fluid fuel which is provided with a heatexchanger in which heat is transferred from a tubular combustion chamber to a liquid heat carrier medium, and which includes a fuel pump, a blower for combustion air, and an electric drive motor, the combustion chamber, heat exchanger, and blower for combustion air being disposed in acoaxial relationship.

2. Description of the Prior Art Heaters for vehicles should meet certain requirements, particularly in respect to compactness, accessibility of the parts of the burner unit, and good controllability to ensure optimum adjustment of heat output and stability of combustion. Various heaters for vehi- 1 cles have been suggested by the prior art, but none of them combines the above requirements in an optimal manner, the known solutions being either too bulky and too costly, or very difficult to service, and sometimes unreliable in operation.

SUMMARY OF THE INVENTION The object of the present invention is to provide a heater which substantially fulfills all of the abovementioned requirements.

The invention suggests a heater for a vehicle comprising, in a casing formed of two separate parts, a fluid fuel pump provided with an atomizing nozzle, and a blower supplying air for the combustion of the fuel, the pump, nozzle and blower being coaxially disposed inside the casing, and being connected to a common drive motor on one side of the casing, while the atomizing nozzle feeds fuel to a combustion chamber located on the opposite side of the casing.

In one convenient form, a heater in accordance with the invention may comprise the following features in combination:

a. an atomizer nozzle disposed coaxially with the drive motor for atomizing the fuel into the combustion chamber;

b. a fuel pump located between the atomizer nozzle and the blower for combustion air;

c. a drive motor located behind the blower for combustion air, as viewed from the atomizer nozzle; and

d. a casing formed of parts separable from one another in a plane between the blower for combustion air and the atomizer nozzle, this casing accommodating the impeller for combustion air, the fuel pump, and the atomizer nozzle.

Feature (a) ensures good electric controllability of the heater and good atomization of the fuel, thus ensuring trouble-free operation of the burner for a long period of time. Incorporation of feature (d) in combination with feature (a) renders the atomizer nozzle readily accessible, while feature (b) provides a simple construction connecting the atomizer nozzle and the fuel pump. Feature (d) also provides easy accessibility to the fuel pump, while allowing it to be accommodated in a protected location. The drive motor is nevertheless readily accessible in view of feature (c), so that the collector brushes of the motor can be attended to or replaced without dismantling the heater. The combination of the features as indicated provides a narrow space-saving construction which can therefore easily be accommodated in a vehicle, and which, as the result of feature (b), entails no sharp changes of direction of air flow to the blower for the combustion air, thereby eliminating any pressure losses detrimental to the stability of combustion.

In a preferred embodiment of the invention there is provided, to connect the separable parts of the casing, a swivelling device to allow a part, e.g. the rear half of the casing, to be swung out carrying with it the drive motor, the parts driven by the latter, and the support of the atomizer nozzle, which is also attached onto to this half of the casing. The swivelling means may be provided at each of two oppositely situated points of the casing, selectively removable swivel pins being provided at these points. In a preferred arrangement, the casing includes a swivel pin on the side opposite to the combustion air intake and one or several quickly releasable swivel bolts with wing nuts on the periphery of the dividing joint, which firmly clamp the casing parts together.

In order to simplify assembly and servicing of the device, the fuel pipe leading to the fuel pump may extend into the casing through the dividing joint of the separable casing parts.

The drive motor may be housed inside a chamber formed by a hood which is likewise fastened on the rear part of the casing, and which has an opening whose center axis forms an angle between and with the axis of the motor. The drive motor located in accordance with feature (c) is thereby protected, while in addition simple adjustability of the flow of combustion air at said opening is also possible.

BRIEF DESCRIPTION OF THE DRAWING Further special features and advantages of the invention will become apparent from the description following below, when taken together with the accompanying drawing which illustrates, by way of an example, an embodiment of the invention, represented as follows:

the sole FIGURE shows in a longitudinal center cross-section a horizontal heater for vehicles representing an embodiment of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT A tubular combustion chamber 1 is surrounded by an annular exhaust gas duct 2 closed at one end, which together with a surrounding cylindrical chamber 3 constitutes a heat exchanger transferring heat to a liquid heat carrier medium. The burner unit consists of an electric drive motor 4, an impeller 5 for combustion air, a fuel pump 6, and an atomizer nozzle 7, the last three parts mentioned being disposed in a casing formed of separable parts, namely a carrier part 8 and a front part 10 carrying a burner head 9. In the plane of the dividing joint between the two parts, the casing includes a swivel pin 11 and one or more swivel bolts 12 and wing nuts which are arranged on the periphery of the joint. The swivel bolts can be quickly released, so that the carrier part 8 can be pivoted around pin 11, and out of the front part 10, for convenient access to the inner parts of the burner assembly. It is also possible to arrange removable swivel pins at both sides of the dividing joint, for example at points 11 and 12, thereby permitting opening of the carrier part in two different directions.

The burner assembly is mounted inside the carrier part 8 on an open flange traversed by three ribs, one of them being shown at 13. The drive motor 4 is mounted in the chamber which is formed by the hood l4, and into which the blower 5 draws the combustion air through the intake aperture 16, delivering it through an annular passage 17 to the burner head 9 and into the combustion chamber 1.

The fuel arrives from a tank (not shown) through the fuel line 18 to the fuel pump 6, which is driven directly, or through a transmission, by the drive motor 4. The nozzle support 19 is fastened to the casing of the pump 6. It is also possible for the fuel line 18 to be passed through the dividing joint between the two separable casing parts 8 and 10.

An exhaust gas outlet 20 extends from the duct 2, while two elbow connections form an intake 21 and outlet 22 for the heat exchanger through which circulates the heat carrier medium. The latter is pumped by a circulating pump (not shown) through the water jacket 3 and into the heating system (likewise not shown).

The invention is not restricted to the details of the embodiment of the invention here illustrated, but may be modified to meet various conditions and requirements encountered, without departing from the scope of the invention.

I claim:

1. A compact fluid-fuel-flred heater for use in vehicles and the like comprising in combination:

a central casing having a longitudinal center axis;

an electric motor mounted axially on one end of the casing;

a combustion air blower in the form of an impeller driven by the electric motor, the blower supplying combustion air through the casing;

a combustion chamber extending from the other axial end of the casing;

a heat exchanger extending from the same end of the casing and arranged in correlation with the combustion chamber, so that during operation, the combustion heat is transferred to a heat carrier medium circulating through the heat exchanger;

a burner head forming an axial communicating passage between the casing and the combustion chamber;

a fuel atomizing nozzle arranged in the center of the burner head so as to aim its fuel discharge axially through the communicating passage into the combustion chamber, and

means for feeding fuel to the atomizing nozzle from a fuel reservoir, the fuel feeding means including a fuel pump driven by the electric motor, the atomizing nozzle being mounted on the fuel pump;

the electric motor and the impeller driven by the motor being arranged substantially in axial alignment with the atomizing nozzle so as to create an annular axially directed flow of combustion air around the atomizing nozzle into the combustion chamber.

2. A vehicle heater as defined in claim ll, wherein the combustion chamber is in the form of a coaxially extending combustion cylinder open at the far end and surrounded by a closed coaxial cylinder so as to create an axial flow gap at the open end of the combustion cylinder and an annular reverse flow gap between the cylinder walls, the combustion chamber further including a radially oriented exhaust outlet near the inner end of the reverse flow gap; and v the heat exchanger includes still another coaxial, closed cylinder surrounding the outer cylinder of the combustion chamber, so as to form an annular jacket for a heat carrier medium, the jacket including an inlet and outlet for the circulation of the heat carrier medium.

3. A vehicle heater as defined in claim 1, wherein the electric motor, the fuel pump, and the atomizer nozzle mounted thereon are arranged substantially coaxially in relation to the drive shaft of the electric motor.

4. A vehicle heater as defined in claim 3, wherein the casing, on the side of the electric motor, includes an open flange traversed by ribs to support the electric motor in the center of the flange, the electric motor having a drive shaft extending to the inside of the casing and carrying the impeller thereon; and

the fuel pump is arranged likewise coaxially inside the casing, in the space between the impeller and the atomizing nozzle, and being driven via the aforementioned motor shaft;

the casing further including acentral air guide in the form of a cone to deflect the combustion air annularly around the fuel pump and to support the latter as well as the atomizer nozzle, the air guide being connected to the casing by radial ribs.

5. A vehicle heater as defined in claim 4, wherein the electric motor and the open flange on which it is mounted are surrounded by a closed, hood-shapd motor cover which includes an intake aperture for the supply of combustion air.

6. A vehicle heater as defined in claim 4, wherein the casing is openable along a radial dividing joint which separates the casing into two axial halves.

7. A vehicle heater as defined in claim 6, wherein the casing further includes, in the plane of the dividing joint, a peripheral pivot pin engaged by both axial halves and quick-release fasteners holding the two halves together; the motor cover, motor, central air guide, fuel pump and atomizer nozzle being arranged as a burner assembly on, and partially inside, one of the casing halves, while the burner head, combusion chamberv and heat exchanger are attached to the other casing half; so that, when the two halves are pivoted open around the peripheral pivot, the fuel pump and atomizer nozzle become conveniently accessible.

8. A vehicle heater as defined in claim 7, wherein the casing includes two oppositely positioned peripheral pivot pins to make possible pivoting around either pin, when the other is removed.

9. A vehicle heater as defined in claim 6, wherein the fuel pump includes a radially extending fuel supply line, the fuel line being arranged in the dividing joint between the casing halves.

10. A fluid-fuel-fired heater for use in vehicles and the like comprising in combination:

a central casing assembly formed by a first casing half and a second casing half which are separable along a casing joint arranged in a plane transverse to the center axis of the casing assembly;

an air and fuel supply assembly mounted in the center axis of the first casing half;

the casing joint including a pivot connection at a distance from the casing center axis and quick-release clamping means opposite the pivot connection, the pivot being so positioned that the casing halves can be swung open so as to expose the atomizing nozzle and the fuel pump for easy access 11. A vehicle heater as defined in claim 10, wherein the air and fuel supply assembly is so mounted on the first casing half that the airflow created by the impeller flows axially around said assembly and through the burner head into the combustion chamber. 

1. A compact fluid-fuel-fired heater for use in vehicles and the like comprising in combination: a central casing having a longitudinal center axis; an electric motor mounted axially on one end of the casing; a combustion air blower in the form of an impeller driven by the electric motor, the blower supplying combustion air through the casing; a combustion chamber extending from the other axial end of the casing; a heat exchanger extending from the same end of the casing and arranged in correlation with the combustion chamber, so that during operation, the combustion heat is transferred to a heat carrier medium circulating through the heat exchanger; a burner head forming an axial communicating passage between the casing and the combustion chamber; a fuel atomizing nozzle arranged in the center of the burner head so as to aim its fuel discharge axially through the communicating passage into the combustion chamber, and means for feeding fuel to the atomizing nozzle from a fuel reservoir, the fuel feeding means including a fuel pump driven by the electric motor, the atomizing nozzle being mounted on the fuel pump; the electric motor and the impeller driven by the motor being arranged substantially in axial alignment with the atomizing nozzle so as to create an annular axially directed flow of combustion air around the atomizing nozzle into the combustion chamber.
 2. A vehicle heater as defined in claim 1, wherein the combustion chamber is in the form of a coaxially extending combustion cylinder open at the far end and surrounded by a closed coaxial cylinder so as to create an axial flow gap at the open end of the combustion cylinder and an annular reverse flow gap between the cylinder walls, the combustion chamber further including a radially oriented exhaust outlet near the inner end of the reverse flow gap; and the heat exchanger includes still another coaxial, closed cylinder surrounding the outer cylinder of the combustion chamber, so as to form an annular jacket for a heat carrier medium, the jacket including an inlet and outlet for the circulation of the heat carrier medium.
 3. A vehicle heater as defined in claim 1, wherein the electric motor, the fuel pump, and the atomizer nozzle mounted thereon are arranged substantially coaxially in relation to the drive shaft of the electric motor.
 4. A vehicle heater as defined in claim 3, wherein the casing, on the side of the electric motor, includes an open flange traversed by ribs to support the electric motor in the center of the flange, the electric motor having a drive shaft extending to the inside of the casing and carrying the impeller thereon; and the fuel pump is arranged likewise coaxially inside the casing, in the space between the impeller and the atomizing nozzle, and being driven via the aforementioned motor shaft; the casing further including a central air guide in the form of a cone to deflect the combustion air annularly around the fuel pump and to support the latter as well as the atomizer nozzle, the air guide being connected to the casing by radial ribs.
 5. A vehicle heater as defined in claim 4, wherein the electric motor and the open flange on which it is mounted are surrounded by a closed, hood-shapd motor cover which includes an intake aperture for the supply of combustion air.
 6. A vehicle heater as defined in claim 4, wherein the casing is openable along a radial dividing joint which separates the casing into two axial halves.
 7. A vehicle heater as defined in claim 6, wherein the casing further includes, in the plane of the dividing joint, a peripheral pivot pin engaged by both axial halves and quick-release fasteners holding the two halves together; the motor cover, motor, central air guide, fuel pump and atomizer nozzle being arranged as a burner assembly on, and partially inside, one of the casing halves, while the burner head, combusion chamber and heat exchanger are attached to the other casing half; so that, when the two halves are pivoted open around the peripheral pivot, the fuel pump and atomizer nozzle become conveniently accessible.
 8. A vehicle heater as defined in claim 7, wherein the casing includes two oppositely positioned peripheral pivot pins to make possible pivoting around either pin, when the other is removed.
 9. A vehicle heater as defined in claim 6, wherein the fuel pump includes a radially extending fuel supply line, the fuel line being arranged in the dividing joint between the casing halves.
 10. A fluid-fuel-fired heater for use in vehicles and the like comprising in combination: a central casing assembly formed by a first casing half and a second casing half which are separable along a casing joint arranged in a plane transverse to the center axis of the casing assembly; an air and fuel supply assembly mounted in the center axis of the first casing half; a combustion chamber and heat exchanger assembly mounted on the second casing half; the air and fuel supply assembly including an electric motor, an air impellor and a fuel pump, both driven by the motor, and a fuel atomizing nozzle extending axially from the fuel pump into the second casing half; the combustion chamber and heat exchanger assembly including a hollow burner head so arranged in the center axis of the second casing half that the atomizing nozzle reaches into the bruner head and discharges fuel through the latter into the combustion chamber; and the casing joint including a pivot connection at a distance from the casing center axis and quick-release clamping means opposite the pivot connection, the pivot being so positioned that the casing halves can be swung open so as to expose the atomizing nozzle and the fuel pump for easy access.
 11. A vehicle heater as defined in claim 10, wherein the air and fuel supply assembly is so mounted on the first casing half that the airflow created by the impeller flows axially around said assembly and through the burner head into the combustion chamber. 